NM_000218.3:c.502G>C

Variant names:

• chr11-2570652-G-C
• rs179489
• NM_000218.3:c.502G>C

Variant summary

Our verdict is Pathogenic. The variant received 31 ACMG points: 31P and 0B. PS1_Very_Strong PS3 PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.502G>C​(p.Gly168Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,328 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000234380: Published functional studies demonstrate that p.(G168R) (nucleotide change not specified) results in lost or reduced channel function (Westenskow et al., 2004" and additional evidence is available in ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G168E) has been classified as Likely pathogenic. The gene KCNQ1 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6 O:1
• Conservation: PhyloP100: 9.44
• Publications: 25 publications found

Genes affected

KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]

KCNQ1 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 1

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Jervell and Lange-Nielsen syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• atrial fibrillation, familial, 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• short QT syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
• short QT syndrome type 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Specifications for KCNQ1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 31 ACMG points.

• PS1: Transcript NM_000218.3 (KCNQ1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000234380: Published functional studies demonstrate that p.(G168R) (nucleotide change not specified) results in lost or reduced channel function (Westenskow et al., 2004; Jons et al., 2011); SCV000737802: This variant has been reported to result in loss of ion channel function in vitro (Westenskow, 2004).; SCV001590790: Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 15051636, 22456477).; SCV004827271: "In vitro functional studies on HEK293 cells and X. laevis oocytes have demonstrated that this missense substitution p.Gly168Arg affects KCNQ1 channel function and cause reduced channel current." PMID: 22456477, 15051636
• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 uncertain in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-2570653-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2720466.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome, Jervell and Lange-Nielsen syndrome 1, long QT syndrome 1, familial atrial fibrillation, short QT syndrome type 2, long QT syndrome, atrial fibrillation, familial, 3, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• PP5: Variant 11-2570652-G-C is Pathogenic according to our data. Variant chr11-2570652-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 53053.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	NM_000218.3	MANE Select	c.502G>C	p.Gly168Arg	missense	Exon 3 of 16	NP_000209.2
	KCNQ1	NM_001406836.1		c.502G>C	p.Gly168Arg	missense	Exon 3 of 15	NP_001393765.1
	KCNQ1	NM_001406837.1		c.232G>C	p.Gly78Arg	missense	Exon 4 of 17	NP_001393766.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.502G>C	p.Gly168Arg	missense	Exon 3 of 16	ENSP00000155840.2	P51787-1
	KCNQ1	ENST00000335475.6	TSL:1	c.121G>C	p.Gly41Arg	missense	Exon 3 of 16	ENSP00000334497.5	P51787-2
	KCNQ1	ENST00000910997.1		c.499G>C	p.Gly167Arg	missense	Exon 3 of 16	ENSP00000581056.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249646 AF XY: 0.00000739

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460328 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726574

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51996

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111932

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Cardiovascular phenotype (2)
2	-	-	Long QT syndrome (2)
2	-	-	not provided (2)
-	-	-	Congenital long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	D
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.5	M
PhyloP100		9.4
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.021	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.90		Gain of methylation at G168 (P = 0.0225)
MVP		0.98
MPC		2.5
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.96
gMVP		0.99
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs179489; hg19: chr11-2591882;